package network;

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.Scanner;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

public class TcpEchoServer {
  private ServerSocket serverSocket = null;

  public TcpEchoServer(int port) throws IOException {
      serverSocket = new ServerSocket(port);
  }

  public void start() throws IOException {
      System.out.println("服务器启动");
      ExecutorService executorService = Executors.newCachedThreadPool();
      while (true) {
          Socket clientSocket = serverSocket.accept();
          executorService.submit(new Runnable() {
              @Override
              public void run() {
                  processConnection(clientSocket);
              }
          });
      }

  }

    private void processConnection(Socket clientSocket) {
        System.out.printf("[%s:%d] 客户端上线!\n", clientSocket.getInetAddress(), clientSocket.getPort());
        try ( InputStream inputStream = clientSocket.getInputStream();
              OutputStream outputStream = clientSocket.getOutputStream()){
           while (true) {
               Scanner scanner = new Scanner(inputStream);
               if (!scanner.hasNext()) {
                   System.out.printf("[%s:%d] 客户端下线!\n", clientSocket.getInetAddress(), clientSocket.getPort());
                   break;
               }
               String request = scanner.next();
               String response = process(request);
               PrintWriter printWriter = new PrintWriter(outputStream);
               printWriter.println(response);
               printWriter.flush();
               System.out.printf("req = %s   resp = %s \n", request, response);
           }
        } catch (IOException e) {
            throw new RuntimeException(e);
        } finally {
            try {
                clientSocket.close();
            } catch (IOException e) {
                throw new RuntimeException(e);
            }
        }
    }

    private String process(String request) {
        return request;
    }

    public static void main(String[] args) throws IOException {
        TcpEchoServer server = new TcpEchoServer(9090);
        server.start();
    }
}
